Stephen Colbert?
Hilarious, indeed! Thanks for posting that link.
I’d like to see Amy Sedaris host, just because I want to see if she’s funny as not-Jerri Blank. I’d also like to see Kristen Schaal (Mel from Flight of the Conchords); her stand-up is pretty funny, even if her voice gets annoying after a while. Maria Bamford would be excellent, I bet. I doubt any of these ladies would be asked to host, though.
I was going to say Catherine O’Hara, but I checked the list and she hosted in 1991 and 1992. I’ll have to track those down.
For the men, I’d love to see Sam Rockwell, James Callis (Gaius Baltar), and Ed Helms.
But I’d rather have them wait until the show is at least a little bit good again. I keep watching it because I like the idea of SNL, but I very rarely even smile at it these days. Really bad writing, I think.
If you look past the superficial cultural deluge of Internet porn, etc., ISTM America’s getting just a bit too wholesome . . . Going to Heaven in a handbasket . . . We need a real flaming asshole known for sexual excesses and embarrassing, inconsiderate behavior. I nominate Andy Dick.
Oops-- just looked up “Beyond The Fringe” and they’re not all host material, a couple of them being a bit on the dead side…
Carry on.
Carol Burnett. In the early days of the show, Burnett is what they made a deliberate effort to get away from in their humor; I think she could hold her own with them!
Tiger Woods
Adam West.
Adam West
Burt Ward.
Naw, I can’t say THAT with a straight face!
Mel Brooks & Carl Reiner- I would like to see them.
Yes! That is a great choice! Though most of America probably has no idea what he looks like, he could do a ton of skits in the voices of the Simpsons characters (if FOX would let him though). In the same vein, maybe Seth McFarlane can host too and he can do his Family Guy voices. It would be hilarious to see in real life what cartoons can get away with. Lots of the things that happen in those cartoons wouldnt be allowed in a life-action show. Quagmire trying to fuck one of the female cast members and getting arrested. Peter Griffin flashing back to something and the scene changes to show the flashback. Homer choking Bart and he actually dies. 
I can’t believe that SNL has never invited Weird Al Yankovic to either perform or host/perform. A couple of years ago in some interview he was asked why he’s never been on the show, and his response was “they’ve never asked me to be”.
I can forgive the rest of that episode for Conan’s portrayal of Moleculo.
EL HOMBRE DE LOS MOLECULOS!
To the OP, you really need to do yourself a favor and find the original full 1992 show when Seinfeld hosted. I consider it to be the best single SNL episode ever (at least on par with Tom Hanks on his “5-timer” episode and any given Chistopher Walken episode). “Stand Up and Win” and “Elijah the Prophet” are both all-time classics from that show (if memory serves).
Seth MacFarlane.
Sarah Silverman
Has William Shatner ever hosted? Leonard Nimoy? Simon Cowell?
To this day I’m disappointed that Sean Connery never showed up for real on a Celebrity Jeopardy to send himself up.
Shatner did host, and did well. The show featured a skit in which he imagined a Star Trek convention as he’d like it to be, during which he famously told the assembled Trekkies “Get a LIFE!!!”
I like to see shows with older, established movie (not TV) actor/actresses generally not known for comedy cutting up. When they’re good, like Christopher Walken and Leslie Nielsen were, it’s awesome. (Of course, by the time he hosted, Nielsen was already well known for doing really funny comedy via the Airplane! and Police Squand/Naked Gun franchises, but you know what I mean.) Sigourney Weaver’s done OK, too. DeNiro… not so much. Didn’t see the one with John Malkovich.
Philip Seymour Hoffman comes to mind. He’s a really versatile actor and he just strikes me as someone who might be really funny.
Nathan Fillion
David Boreanz
When the NY Giants won the Superbowl a couple years ago, I thought SNL missed an opportunity to have Eli Manning host. Payton Manning already hosted when the Colts won and he was pretty funny (the skit with the basketball team getting a halftime peptalk from the coach in particulat), so it would be funny to have Payton come out for the monologue and start talking about how great it is to be in NY and hosting, etc etc, then start talking about how it was great to win the Superbowl. Eli can then come out and say that he already hosted and now it’s his turn. Payton can then make a whining aw come on kind of thing, then either Archie or their mom can tell him that it’s his brother’s turn, then Payton puts and stomps off the stage.